Ring interferometer

摘要

A ring interferometer comprises a light source, an optical beam splitting device for receiving light from the light source, a light path encircling an area at least once and opening at both ends into the optical beam splitting device and a photodetector for detecting light from the light path. The light which enters the light path and is coupled to the optical beam splitting device at both ends passes through the light path in both directions. The light then reunites in the beam splitting device and thereby is brought into interference which is detected by the photodetector. The light source is chosen to produce light which has a coherence time which is substantially shorter than the propagation time of light through the light path.